Function used to set up R2D2 priors for population-level effects in
brms. The function does not evaluate its arguments -- it exists purely
to help set up the model.
mean of the Beta prior on the coefficient of determination R^2.
prec_R2
precision of the Beta prior on the coefficient of determination R^2.
cons_D2
concentration vector of the Dirichlet prior on the variance
decomposition parameters.
autoscale
Logical; indicating whether the R2D2
prior should be scaled using the residual standard deviation
sigma if possible and sensible (defaults to TRUE).
Autoscaling is not applied for distributional parameters or
when the model does not contain the parameter sigma.
References
Zhang, Y. D., Naughton, B. P., Bondell, H. D., & Reich, B. J. (2020).
Bayesian regression using a prior on the model fit: The R2-D2 shrinkage
prior. Journal of the American Statistical Association.
https://arxiv.org/pdf/1609.00046.pdf